scholarly journals DLG2 Impairs dsDNA Break Repair and Maintains Genome Integrity in Neuroblastoma

2021 ◽  
Author(s):  
Simon Keane ◽  
Hendrik A. de Weerd ◽  
Katarina Ejeskär
Keyword(s):  
Neuroblastoma Cell ◽  
Fruit Fly ◽  
Strand Break ◽  
Suppressor Gene ◽  
Dependent Manner ◽  
Dna Breaks ◽  
Functional Studies ◽  
Gene And Protein Expression ◽  
Break Repair ◽  
Neuroblastoma Patient

Abstract Background: In primary neuroblastoma, deletions on chromosome 11q are known to result in an increase in the total number of chromosomal breaks. Microhomology mediated-end joining (MMEJ) is an error-prone pathway for DNA double-strand break repair that is often upregulated in cancer. DLG2, a candidate tumor suppressor gene on chromosome 11q, has previously been implicated in DNA repair.Methods: We evaluated an association between MMEJ gene expression and neuroblastoma patient outcome, risk categorization, and 11q status using publicly available microarray data from independent neuroblastoma patient datasets. Functional studies were conducted using comet assay and H2AX phosphorylation in neuroblastoma cell lines and in the fruit fly with UVC-induced DNA breaks. Results: We show that the MMEJ genes PARP1 and FEN1 are over expressed in neuroblastoma and restoration of DLG2 impairs their gene and protein expression. When exposed to UVC radiation, cells with DLG2 over expression show less DNA fragmentation and induce apoptosis in a p53 S46 dependent manner. We could also confirm that DLG2 expression results in CHK1 phosphorylation consistent with previous reports of G2/M maintenance. Conclusions: Taken together, we show that DLG2 expression increases p53 mediated apoptosis in response to genotoxicity, by maintaining S317 CHK1 phosphorylation and reducing the DNA replication machinery.

scholarly journals YGR042W/MTE1 Functions in Double-Strand Break Repair with MPH1

2015 ◽  
Author(s):  
Askar Yimit ◽  
TaeHyung Kim ◽  
Ranjith Anand ◽  
Sarah Meister ◽  
Jiongwen Ou ◽  
...  
Keyword(s):  
Dna Damage ◽  
Strand Break ◽  
Double Strand Break ◽  
Dna Helicase ◽  
Double Strand Breaks ◽  
Double Strand Break Repair ◽  
Dependent Manner ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Break Repair

Double-strand DNA breaks occur upon exposure of cells to agents such as ionizing radiation and ultraviolet light or indirectly through replication fork collapse at DNA damage sites. If left unrepaired double-strand breaks can cause genome instability and cell death. In response to DNA damage, proteins involved in double-strand break repair by homologous recombination re-localize into discrete nuclear foci. We identified 29 proteins that co-localize with the recombination repair protein Rad52 in response to DNA damage. Of particular interest, Ygr042w/Mte1, a protein of unknown function, showed robust colocalization with Rad52. Mte1 foci fail to form when the DNA helicase Mph1 is absent. Mte1 and Mph1 form a complex, and are recruited to double-strand breaks in vivo in a mutually dependent manner. Mte1 is important for resolution of Rad52 foci during double-strand break repair, and for suppressing break-induced replication. Together our data indicate that Mte1 functions with Mph1 in double-strand break repair.

scholarly journals Resveratrol modulates DNA double-strand break repair pathways in an ATM/ATR–p53- and –Nbs1-dependent manner

2008 ◽  
Vol 29 (3) ◽  
pp. 519-527 ◽  
Author(s):  
Susanne Andrea Gatz ◽  
Marlen Keimling ◽  
Cindy Baumann ◽  
Thilo Dörk ◽  
Klaus-Michael Debatin ◽  
...  
Keyword(s):  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
Dependent Manner ◽  
Dna Double Strand Break ◽  
Repair Pathways ◽  
Break Repair

scholarly journals Novel PNKP mutations causing defective DNA strand break repair and PARP1 hyperactivity in MCSZ

2019 ◽  
Vol 5 (2) ◽  
pp. e320 ◽  
Author(s):  
Ilona Kalasova ◽  
Hana Hanzlikova ◽  
Neerja Gupta ◽  
Yun Li ◽  
Janine Altmüller ◽  
...  
Keyword(s):  
Topoisomerase I ◽  
Strand Break ◽  
Neurologic Disease ◽  
Dna Breaks ◽  
Novel Mutations ◽  
Molecular Feature ◽  
Single Strand Break ◽  
Dna Strand Break ◽  
Break Repair ◽  
Dna Strand

ObjectiveTo address the relationship between novel mutations in polynucleotide 5'-kinase 3'-phosphatase (PNKP), DNA strand break repair, and neurologic disease.MethodsWe have employed whole-exome sequencing, Sanger sequencing, and molecular/cellular biology.ResultsWe describe here a patient with microcephaly with early onset seizures (MCSZ) from the Indian sub-continent harboring 2 novel mutations in PNKP, including a pathogenic mutation in the fork-head associated domain. In addition, we confirm that MCSZ is associated with hyperactivation of the single-strand break sensor protein protein poly (ADP-ribose) polymerase 1 (PARP1) following the induction of abortive topoisomerase I activity, a source of DNA strand breakage associated previously with neurologic disease.ConclusionsThese data expand the spectrum of PNKP mutations associated with MCSZ and show that PARP1 hyperactivation at unrepaired topoisomerase-induced DNA breaks is a molecular feature of this disease.

scholarly journals Evidence for Biased Holliday Junction Cleavage and Mismatch Repair Directed by Junction Cuts during Double-Strand-Break Repair in Mammalian Cells

2001 ◽  
Vol 21 (10) ◽  
pp. 3425-3435 ◽  
Author(s):  
Mark D. Baker ◽  
Erin C. Birmingham
Keyword(s):  
Homologous Recombination ◽  
Mismatch Repair ◽  
Mammalian Cells ◽  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
Holliday Junction ◽  
Chromosomal Dna ◽  
Dna Breaks ◽  
Break Repair

ABSTRACT In mammalian cells, several features of the way homologous recombination occurs between transferred and chromosomal DNA are consistent with the double-strand-break repair (DSBR) model of recombination. In this study, we examined the segregation patterns of small palindrome markers, which frequently escape mismatch repair when encompassed within heteroduplex DNA formed in vivo during mammalian homologous recombination, to test predictions of the DSBR model, in particular as they relate to the mechanism of crossover resolution. According to the canonical DSBR model, crossover between the vector and chromosome results from cleavage of the joint molecule in two alternate sense modes. The two crossover modes lead to different predicted marker configurations in the recombinants, and assuming no bias in the mode of Holliday junction cleavage, the two types of recombinants are expected in equal frequency. However, we propose a revision to the canonical model, as our results suggest that the mode of crossover resolution is biased in favor of cutting the DNA strands upon which DNA synthesis is occurring during formation of the joint molecule. The bias in junction resolution permitted us to examine the potential consequences of mismatch repair acting on the DNA breaks generated by junction cutting. The combination of biased junction resolution with both early and late rounds of mismatch repair can explain the marker patterns in the recombinants.

scholarly journals RNF4 regulates DNA double-strand break repair in a cell cycle-dependent manner

Cell Cycle ◽  
2016 ◽  
Vol 15 (6) ◽  
pp. 787-798 ◽  
Author(s):  
Ching-Ying Kuo ◽  
Xu Li ◽  
Jeremy M. Stark ◽  
Hsiu-Ming Shih ◽  
David K. Ann
Keyword(s):  
Cell Cycle ◽  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
Dependent Manner ◽  
Dna Double Strand Break ◽  
A Cell ◽  
Break Repair ◽  
Cycle Dependent

scholarly journals JNK Phosphorylates SIRT6 to Stimulate DNA Double-Strand Break Repair in Response to Oxidative Stress by Recruiting PARP1 to DNA Breaks

Cell Reports ◽  
2016 ◽  
Vol 16 (10) ◽  
pp. 2641-2650 ◽  
Author(s):  
Michael Van Meter ◽  
Matthew Simon ◽  
Gregory Tombline ◽  
Alfred May ◽  
Timothy D. Morello ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
Dna Breaks ◽  
Dna Double Strand Break ◽  
Break Repair

scholarly journals Single-Strand DNA Breaks Cause Replisome Disassembly

2020 ◽  
Author(s):  
Kyle B. Vrtis ◽  
James M. Dewar ◽  
Gheorghe Chistol ◽  
R. Alex Wu ◽  
Thomas G. W. Graham ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Genome Stability ◽  
Strand Break ◽  
Dna Lesions ◽  
Single Strand ◽  
List Type ◽  
Dependent Manner ◽  
Dna Breaks ◽  
Leading Strand ◽  
Lagging Strand

SummaryDNA damage impedes replication fork progression and threatens genome stability. Upon encounter with most DNA adducts, the replicative CMG helicase (CDC45-MCM2-7-GINS) stalls or uncouples from the point of synthesis, yet CMG eventually resumes replication. However, little is known about the effect on replication of single-strand breaks or “nicks”, which are abundant in mammalian cells. Using Xenopus egg extracts, we reveal that CMG collision with a nick in the leading strand template generates a blunt-ended double-strand break (DSB). Moreover, CMG, which encircles the leading strand template, “runs off” the end of the DSB. In contrast, CMG collision with a lagging strand nick generates a broken end with a single-stranded overhang. In this setting, CMG translocates beyond the nick on double-stranded DNA and is then actively removed from chromatin by the p97 ATPase. Our results show that nicks are uniquely dangerous DNA lesions that invariably cause replisome disassembly, and they argue that CMG cannot be deposited on dsDNA while cells resolve replication stress.HighlightsThe structures of leading and lagging strand collapsed forks are differentCMG passively “runs off” the broken DNA end during leading strand fork collapseCMG is unloaded from duplex DNA after lag collapse in a p97-dependent mannerNicks are uniquely toxic lesions that cause fork collapse and replisome disassembly

scholarly journals RAD51 paralogs regulate double strand break repair pathway choice by limiting Ku complex retention

2018 ◽  
Author(s):  
Fernando Mejías-Navarro ◽  
Daniel Gómez-Cabello ◽  
Pablo Huertas
Keyword(s):  
Control Point ◽  
Strand Break ◽  
Double Strand Break ◽  
Double Strand Break Repair ◽  
Dna Breaks ◽  
Rad51 Paralogs ◽  
Break Repair ◽  
Dna End Resection ◽  
Non Homologous End Joining

AbstractRAD51 paralogs are a group of conserved proteins in eukaryotes that are involved in the repair of DNA breaks at several levels. On one hand, they help the strand invasion step catalyzed by RAD51. Also, they play late roles in Holliday Junction metabolism. Here we uncover a new role of the RAD51 paralogs at an earlier event in the repair of broken chromosomes. All five RAD51 paralogs affect the balance between double strand break repair pathways. Specifically, they favor homology-mediated repair over non-homologous end-joining. Such role is independent of RAD51 or the checkpoint activity of these proteins. Moreover, it defines a novel control point of double strand break repair independent and subsequent to DNA-end resection initiation.Mechanistically, RAD51 paralogs limit the retention of Ku80 at the sites of DNA breaks. Thus, our data extend the role of this family of proteins to the earliest event of double strand break repair.

scholarly journals Molecular cloning of the human XRCC1 gene, which corrects defective DNA strand break repair and sister chromatid exchange.

1990 ◽  
Vol 10 (12) ◽  
pp. 6160-6171 ◽  
Author(s):  
L H Thompson ◽  
K W Brookman ◽  
N J Jones ◽  
S A Allen ◽  
A V Carrano
Keyword(s):  
Ionizing Radiation ◽  
Sister Chromatid ◽  
Sister Chromatid Exchange ◽  
Strand Break ◽  
Cosmid Clone ◽  
Dna Breaks ◽  
Xrcc1 Gene ◽  
Restriction Endonuclease Site ◽  
Break Repair ◽  
Higher Sensitivity

We describe the cloning and function of the human XRCC1 gene, which is the first mammalian gene isolated that affects cellular sensitivity to ionizing radiation. The CHO mutant EM9 has 10-fold-higher sensitivity to ethyl methanesulfonate, 1.8-fold-higher sensitivity to ionizing radiation, a reduced capacity to rejoin single-strand DNA breaks, and a 10-fold-elevated level of sister chromatid exchange compared with the CHO parental cells. The complementing human gene was cloned from a cosmid library of a tertiary transformant. Two cosmid clones produced transformants that showed approximately 100% correction of the repair defect in EM9 cells, as determined by the kinetics of strand break repair, cell survival, and the level of sister chromatid exchange. A nearly full-length clone obtained from the pcD2 human cDNA expression library gave approximately 80% correction of EM9, as determined by the level of sister chromatid exchange. Based on an analysis of the nucleotide sequence of the cDNA insert compared with that of the 5' end of the gene from a cosmid clone, the cDNA clone appeared to be missing approximately 100 bp of transcribed sequence, including 26 nucleotides of coding sequence. The cDNA probe detected a single transcript of approximately 2.2 kb in HeLa polyadenylated RNA by Northern (RNA) blot hybridization. From the open reading frame and the positions of likely start sites for transcription and translation, the size of the putative XRCC1 protein is 633 amino acids (69.5 kDa). The size of the XRCC1 gene is 33 kb, as determined by localizing the endpoints on a restriction endonuclease site map of one cosmid clone. The deduced amino acid sequence did not show significant homology with any protein in the protein sequence data bases examined.

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